<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        //计算两个文本框值的和
        var num1 = prompt("请输入第一个数字：");//字符串
        var num2 = prompt("请输入第二个数字：");

        // console.log(Number(num1) + Number(num2));
        // console.log(parseInt(num1) + parseInt(num2));
        // alert(parseFloat(num1) + parseFloat(num2))
        // alert(1*num1 + 1*num2)
        // alert(num1/1 + num2/1)
        // alert((num1-0) + (num2-0))
        // alert(+num1 + +num2)
    </script>
</body>

</html>